Method of producing insulating mats



June 23, 1936.

w. @ERB METHOD OF RODUCING INSULATING MATS Filed Jan. 23, 1955 h a greater degree of elasticity than the remaining.

Patented June 23,' 1936 PATENToFFlcE Mn'rnon oF rnoDUomG INSULATING Mars Willian een, nerim, .Germany Application January 23, 1935, Serial No. 3,107

In Germany February 14, 1934 y 2- ciaims. (c1. isiasi `It is known per se to produce projections or elevations in a'web of material of thisnature for the purpose of imparting a certain resiliency to the insulating mats made from this web. These projections areobtained by. a stamping or pressing operation. E f

Now according to the inventionfthese projections, at "the same time as the same are raised from the surface of the material,v are loosened in `their structure. In this way the elasticity of the mats is considerably enhanced, as the projections or elevations constitute supporting points having surface of the mats. Owing to the loosening of that portion of the material forming the actual elevations or projections there are produced in the latter small pockets or spaces, as a.I result of whichthe heat-.insulating and sound-deadening properties of mats made in accordance with the invention are considerably improved. .In carrying the invention into effect it is possible to make use of cheap materials, and it is exactly whenusing a cardboard material of this nature that a particularly effective and lextensive loosening .of the material of the projections or elevations is obtainable.

To enhance the effect the projections or elevations may be produced on both sides of the material. Matsproduced according to thewinvention, whilst useful for a variety of purposes, are .particularly suitable'for deadening sound. If desired, they may be placed one upon the other to form a multiple-layer structure, in which case it will be found preferable to arrange the layers in such fashion that the projections or elevations on the one mat are situated next to the recessedA surface of the following mat. Owing to the loosened structure of the material of the elevations or projections the elasticity ofthe entire mat is increased by the fact that the material intermediate of the elevations vor projections l represents a resilient support. I

The invention will now be described more fully .withv reference to the accompanying drawing, in: which-,

Fig. 1 is a section through part of a mat produced according to the invention, taken along the line I--I in Fig. 2.

Fig.- 2 is aI plan view pf the mat according to Fig. 1.

lproducinginsulating mats, which are,l

Fig. 3 shows diagrammatically, partly in section, the primary parts of the apparatus used for producing the mat. Fig. 4 is-a section through part of amat, in which theiprojectionshave been subjected to an additional pressing operation.

Fig. 5 is a section through an additional form of embodiment. of a mat, in which the hollow spaces of the recesses have been lled out with a suitable filling material.

Referring now toFigs. 1 and 2, I is the web of fibrous material fromwhich the. mats are 'produced. In this material there are formed 'by suitable means, of which a possible example will be described later, projections or elevations 2, and l5 accordingly corresponding recesses 3. These projections or elevations are so acted upon during their production that'the material of the projections is loosened in its structure, resulting in the advantages above referred to. The difference in the structure between the material of the projections and the remaining material is represented by the diiferent'cross-hatching in the drawing. i

The loosening of the material ofthe projections or elevations is obtained by the fact that the clearance between the shaping studs or dies and the corresponding matrices is greater than the thickness of the web of material. In this manner the matrix remains practically ineffective as regards the forming of the elevations. The underneath side of the web of" material or mat i may be furnished with a covering layer la connected in suitable fashion with the layer l in order to prevent dust or otherforeign matter from penetrating into the recesses. l

Fig. 3 shows a possible form of apparatus for carrying the invention into effect. This com- \prises two rollers 4 and 15, which rotate about their shaft 6 and 1 in the direction of the arrows. On the roller v4 there are provided studs 8, the roller 5 possessing corresponding recesses or cavities 9.

As shcwnby the drawing, the studs 8 are considerably smaller 'than the recesses 9, both as re- 45 gards their height as well as their diameter. The dimensions are inany case such that the spacing between the studs 8 and the recesses 9 is greaterl thanthe thickness of the material passed between the two` rollers. A l

The web of cardboard or other material employed is designated III, and is passed between the rollers in the direction of the arrow Il in such fashion that the projections or elevations are .formed in the manner referred'to. For the pur- 55 pose of extracting the material from the apparaf tus after the projections have been produced there is provided a special roller I la rotating about the Ashaft I2 at a speed which is greater than that `of the rollers 4 and 5.

Tests made have shown that with the assistance of the roller I I the web of material may be with-l drawn more readily and in more simple fashion vfrom the rollers 4 and 5.

matrix that the material is not held by the latter,

but is capable to a certain -extent of free movement, so that the structure of the material of the projection formed will be loosened accordingly.

Under certain circumstances it may be necessary subsequently to reinforce a mat produced according to the method described in the above, so that the same will not be liable to a permanent variation in form by reason of externally acting forces. According to therinvention, this ,reinforcement is effected .by the fact that after the production of the mat in the normal fashion the mat is subjected to a gentle reverse pressing operation, as illustratedby way of example `in Fig. 4.

4loosened in structure as In order in the case'of part' icularlyheavyl 'strains to prevent `thelooscned projections or elevations from being pressed back, the hollow spaces of these projections may be wholly -or partially illled out with a suitable filling material, 5

preferably a material having elastic properties.

Fig. 6 illustrates by way of example a part of a mat of this description. In this case I is the web of material, 2 are the projections produced therein, and la is anlling substance introduced into 10 the hollow spaces of the projections, this substance preferably being retained within the hollows by means of a covering layer la applied to the surface of the mat.

What I claim las new and desireV to secure by, Letters Patent is: f

1. A method of producing insulating mats composed moreparticularly of a 'fibrous material, such as cardboard, paper and the like, which consists in subjecting the said material to a pressing operation to produce elevations therein, and simultaneously loosening the structure of that portion of the said material constituting the said elevations while at the same time avoiding compressing the loosenedgstructure of the eleva'- 25 tions.

2. An insulating mat composed more particularly of a fibrous material, such as cardboard; paper and the like, having elevations formed'from the material, the material of the elevations being compared with the re maining material.

. WILLIAM GERB. 

